Arc lamp with concentric electrodes



United States Patent Inventors Teddy .1. Peacher:

' Dorwin L. Kilbourn. Huntsville, Ala. [21] Appl. No. 789.526 [22 FiledJan. 7, 1969 [45] Patented Dec. 29, 1970 [73] Assignee The United States01 America as represented by the Secretary of the Army.

[ 54] ARC LAMP WITH CONCENTRIC ELECTRODES 4 Claims, 1 Drawing Fig.

[52] U.S.Cl. 313/110, 3l3/184,313/2l7.313/220 [51] Int. Cl. ..1-1 01j61/06, H01 j 61/30 [50] Field ofSearch 313/184. 209, 210, 217. 220, 231,110(Cursory). 110

[56] Y Re ferences'Cited UNITED STATES PATENTS 2,629,836 2/1953. Deri 3l 3/209X 2.802.130 8/1957 Engelman et a1. 313/210X 3.188.512 6/1965Moore 313/110 3.317.777 5/1967 Algar et a1. 313/182 3.465.194 9/1969Hall 313/217X Primary E.ran1iner-John Kominski Assistant Examiner-PalmerC Demeo Atlorneys- Harry M. Saragovitz. Edward .1. Kelly. Herbert Berland Harold W. Hilton PATENTED UEC29 1975 Teddy J. Pacher DorwinL.Kilbourn, INVENTORS.

AW Lf M 1/ My ARC LAMP WITH CONCENTRIC ELECTRODES BACKGROUND OF THEINVENTION SUMMARY OF THE INVENTION The present invention relates to anarc lamp having a pair of electrodes disposed in spaced concentric'relationyThe electrodes are partially enclosed in an envelope having agas therein disposed for energization responsivelto activation of theelectrodes.

It is an object of the present invention, therefore, to provide an arclamp in which radiation emanates therefrom without being restricted orblocked by internal structure such as electrodes.

It is another object of the present invention to provide such an arclamp in which the electrodes aremounted in concentric relation forunrestricted radiation flow from the lamp.

These and other objects and advantages of the present invention will bemore readily apparent from the following description and drawing.

BRIEF DESCRIPTION OF THE DRAWING The FIG. is an elevational sectionalview of the lamp of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the FIG., an arclamp 10 includes a window 12 of ceramic, quartz or the like, sealed toan annular anode 14 by a metal ferrule 16. Anode l4 isprovided with acentral opening 17 which substantially encloses a tip l8of a hollowcathode 20. Cathode 20 includes a portion 22 extending out of opening17. I

A ceramic insulator 24, in the form of a cylinder or sleeve, partiallyencloses the cathode and is sealed thereto by a ceramic to a metal seal26. Anode 14 is sealed to-the ceramic insulator by a metal seal 28 whichis secured to a metallized band disposed around the insulator 24.

The anode is generally annular in shape with stepped annular shoulders30 and 32 and a conical portion 34 terminating into a flat inner anodereflecting surface 36. The anode structure can also be shaped to serveas a multifunction device including electrode, heat sink, reflector,resonance shield, and basing member. If desired, the anode may havescrew threads on the outer periphery or lugs for bayonet mounting.

The cathode 20 includes a central hollow portion 38 communicating into achamber 40 through passages 39. Chamber 40 is formed by sealing window12 to the anode and the anode to the cathode. An end portion 22 of thecathode is pinched off to seal the opening therein responsive to fillingchamber 40 with gas through passages 38 and 39.

The tip 18 of the cathode may be in the form shown, as a flat recessedsurface, or, if desired, the cathode tip may be shaped as a flat discslightly suspended above the anode. In any event, the tip is of arefractory material, such as tungsten.

Obviously, many modifications of the present invention may be resorted,to by one skilled in the art; however, such modifications are within thespirit and scope of the appended claims.

We claim:

1. An arc lamp comprising:

a. an anode having an annular configuration provided with a firstreflecting surface, said anode having a central opening therethrough; b.a transparent envelope secured around the periphery of said annularanode and forming a chamber between said envelope and said first surfaceof said cathode;

c. a cathode mounted in said opening of said anode, said cathode beingsealed to an inner annular surface of said anode formed by said openingand having a portion extending into said chamber;

(1. a gas disposed in said chamber;

e. means for applying a potential between said cathode and said anode;and

f. passage means provided through said cathode, said passage meansdisposed in communication with said chamber for insertion of said gastherein.

2. A device as set forth in claim 1 including a ceramic insulatingcollar disposed around said cathode in spaced relation thereto, saidcollar being disposed in concentric spaced relation in said opening ofsaid anode, and first seal means secured around said collar and insecured relation to said inner annular surface of said anode forsecuring said cathode in said anode opening, second seal means securedto said cathode and. said insulating collar for retention of saidcathode and said collar in the spaced relation.

3. The device as set forth in claim 2 wherein said envelope is ahemispherical shaped window having the edges mounted on said anode; and,means for sealing said envelope to said anode.

